Vanity Call - When to apply vs expiration date

I was wondering if someone could explain to me when I should apply for a vanity call relative to the call signs current expiration date.
Let’s say the call sign that I want is listed in the FCC database with an expiration date of 4/16/2014.
I thought that the FCC would only accept applications from 4/17/2014 on – one day after it expired. All applications received on that day went into a lottery and one would be selected. If none were received on the first day after the call sign was available, the process would occur on the day the first request for the call sign was received. All on that day go into a lottery …
However I see that some people seem to apply several days before the expiration date and they aren’t reject. Do they get the call sign or are they just put into the first group of people that apply 1 day after the expiration? (Followed the rules). So, how early can I make the application (before the expiration date) and not be rejected?

All applications received on that day went into a lottery and one would be selected. If none were received on the first day after the call sign was available, the process would occur on the day the first request for the call sign was received. All on that day go into a lottery …

Vanity call sign applications submitted less than 2 years and one day after a call sign expiration date will be denied.

It is also my understanding that applications are processed in a random order rather than in the order received.

Here some facts about the timeline for application processing retrieved from an archive.org copy of vanityhq.com:

1. Vanity applications are usually processed on Tuesdays, Fridays, and Saturdays

2. Applications received on Monday are processed on Friday, 18 days later

3. Applications received on Tuesday are processed on Saturday, 18 days later

4. Applications received on Wednesday, Thursday, or Friday are processed on Tuesday, 18 days after the Friday date

5. Holidays occuring between the received date and the processed date don't seem to change the schedule. However, Monday holidays cause the Tuesday processing to be a day late

6. Applications filed on Saturday, Sunday, or a holiday are marked "received" and date stamped the next business day

7. Applications are processed as a batch job in the early morning hours while the ULS system is off-line. If the batch job fails it may cause grants to be delayed

As stated above all entries on a given day are entered into a "lottery" type random selection for processing on the process date. Those entries showing application dates prior to the availability of the call signs are applications which were entered on the date shown and subsequently modified on the same date as all the other applications participting in the "lottery". There is no advantage to this as the applications are selected randomly when processed.